*> 100 Cool Things - http://cobolrocks.codeplex.com/
*> Copyright (c) 2009-2010
*> by Emerson Lopes (emersonlopes@gmail.com)
*>
*> Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated 
*> documentation files (the "Software"), to deal in the Software without restriction, including without limitation 
*> the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and 
*> to permit persons to whom the Software is furnished to do so, subject to the following conditions:
*>
*> The above copyright notice and this permission notice shall be included in all copies or substantial portions 
*> of the Software.
*>
*> THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED 
*> TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
*> THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 
*> CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
*> DEALINGS IN THE SOFTWARE.

CLASS-ID. PowerExpression AS "InterpreterPattern.PowerExpression" inherits ClassNonTerminalExpression.

    environment division.
        configuration section.
            repository.
                class ClassContext                as "InterpreterPattern.Context"
                class SystemString                as "System.String"
                class ClassNonTerminalExpression  as "InterpreterPattern.NonTerminalExpression"
                
                interface IExpression             as "InterpreterPattern.IExpression".
                
 *> Instance's data and methods
    object. 
        data division.
            working-storage section.
            copy "types.book".
            
            01  variable  object reference SystemString private.
            
        procedure division.
        
            method-id. NEW.
                 data division.
                     linkage section.
                     01   inLeftExpression      object reference IExpression.
                     01   inRightExpression     object reference IExpression.
                     
                 procedure division using inLeftExpression, inRightExpression.
                     
                     invoke super "NEW" using inLeftExpression, inRightExpression.
             
            end method NEW.
            
            method-id. EvaluateExpresion as "Evaluate" override.
                data division.
                    working-storage section.
                    
                    01 anExpression   object reference IExpression.
                    
                    linkage section.
                    
                    01 inContext  object reference ClassContext.
                    01 outValue   type SystemDouble.
                
                procedure division using inContext returning outValue.
                
                    invoke super "GetLeftNode" returning anExpression

                    move  anExpression::"Evaluate"(inContext)  to  outValue

                    invoke super "GetRightNode" returning anExpression
                   
                    *> This is the real "PowerExpression"
                   compute outValue = outValue ** anExpression::"Evaluate"(inContext) 
                       
            end method EvaluateExpresion.

    end object.
END CLASS PowerExpression.

